XYplorer Beta Club

They are completely unrelated to each other. Please see the thread that you already created about this.
viewtopic.php?f=3&t=14884

Okay, I'll study that stuff.

What about the fact that UltraEdit (64-bit) shows up on File Explorer's context menu (for every file type so far as I can see), but never on XY's.

"Show the 64-bit context menu" is set.

they might use a 64-bit shell extension that's incompatible with xy, or only compatible with windows explorer

No problem. Other 64-bit programs' items do show up.